diff options
Diffstat (limited to 'kernel/watchdog.c')
| -rw-r--r-- | kernel/watchdog.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 60301916f62e..6e63097fa73a 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -28,7 +28,7 @@ #include <linux/perf_event.h> int watchdog_enabled = 1; -int __read_mostly watchdog_thresh = 60; +int __read_mostly watchdog_thresh = 10; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog); @@ -91,6 +91,17 @@ static int __init nosoftlockup_setup(char *str) __setup("nosoftlockup", nosoftlockup_setup); /* */ +/* + * Hard-lockup warnings should be triggered after just a few seconds. Soft- + * lockups can have false positives under extreme conditions. So we generally + * want a higher threshold for soft lockups than for hard lockups. So we couple + * the thresholds with a factor: we make the soft threshold twice the amount of + * time the hard threshold is. + */ +static int get_softlockup_thresh() +{ + return watchdog_thresh * 2; +} /* * Returns seconds, approximately. We don't need nanosecond @@ -110,7 +121,7 @@ static unsigned long get_sample_period(void) * increment before the hardlockup detector generates * a warning */ - return watchdog_thresh * (NSEC_PER_SEC / 5); + return get_softlockup_thresh() * (NSEC_PER_SEC / 5); } /* Commands for resetting the watchdog */ @@ -182,7 +193,7 @@ static int is_softlockup(unsigned long touch_ts) unsigned long now = get_timestamp(smp_processor_id()); /* Warn about unreasonable delays: */ - if (time_after(now, touch_ts + watchdog_thresh)) + if (time_after(now, touch_ts + get_softlockup_thresh())) return now - touch_ts; return 0; @@ -359,7 +370,7 @@ static int watchdog_nmi_enable(int cpu) /* Try to register using hardware perf events */ wd_attr = &wd_hw_attr; - wd_attr->sample_period = hw_nmi_get_sample_period(); + wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh); event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback); if (!IS_ERR(event)) { printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n"); |